The Nasdaq and S&P 500 fell on Monday, resuming a recent downward trend, with semiconductor shares leading declines on the Nasdaq and oil prices dragging down energy shares.

A semiconductor index <.SOX> was down 1 percent, and remained below its April 2010 high, suggesting more bearish activity after the index broke below its 200-day moving average.

We look for the leaders to lead, and when the leaders aren't leading, it indicates a problem, said John Kosar, director of research at Asbury Research in Chicago.

The Dow Jones industrial average <.DJI> was up 2.20 points, or 0.02 percent, at 11,954.11. The Standard & Poor's 500 Index <.SPX> was down 0.82 points, or 0.06 percent, at 1,270.16. The Nasdaq Composite Index <.IXIC> was down 5.05 points, or 0.19 percent, at 2,638.68.

The Nasdaq 100 <.NDX> fell below its 200-day moving average.

Exxon Mobil Corp declined 0.6 percent to $79.27, while Chevron Corp was down 0.8 percent at $98.87 following a drop of more than $2 a barrel in U.S. oil futures.

More worries about euro zone debt weighed on sentiment after Standard & Poor's cut Greece's credit ratings.

Stocks started the day in positive territory as investors sought bargains after six weeks of declines.

Concerns about a weak global economic recovery have helped push the S&P 500 down 6.8 percent since its May 2 high. Several strategists have called for a correction of about 10 percent in the index from that recent peak.

Some investors may be waiting for the index to fall to the 1,250 psychological mark before taking longer positions, according to Chris Burba, short-term market technician at Standard & Poor's in New York.

(Reporting by Caroline Valetkevitch; editing by Jeffrey Benkoe)